Improvement in grinding-rest for twist-drills



UNITED STATES PATENTOFFIGE.

STEPHEN A. MORSE, OF NEVARK, NEV JERSEY, ASSIGNOR TO AMERICAN STANDARDTOOL COMPANY, OF SAME PLACE.

IMPROVEMENT IN GRINDING-REST FOR -TWlST-DRILLS.

Specification ihr-ming part oi' Letters Patent N0. 104,982, dated July5, 1870.

To all whom it mafyooaoem:

Be it known that I, STEPHEN A. MonsE, ot' Newark, in 'the county ofEssex and State ot' New Jersey, have invented a new and ImprovedGrinding-Rest for Twist-Drills; and I do hereby declare that thefollowing isa full, clear', and exact description thereof, which willenable others skilled in the artto make and use the same, referencebeing had to the accompanying drawing, forming part oi' thisspecification, in which- Figure l represents a plan or top view of myimproved grinding-rest. Fig. 2 is a front elevation of the same.

Similar letters of reference indicate correspending parts.

This invention has for its object to provide an adjustable rest by meansot' which twistdrills may be properly held against grindstones orgrinding-wheels oi' suitable kind.

The invention consists, chiefly, in providing an oblique guide, on whichthe drill can be held and rocked in the same plane, so as to have itsend ground at the desired angle.

The invention consists, also, in providing said guide with an adjustablecurved arm, on which the drill can be moved; and, finally, in thecombination, with the same, of two adjustable holders, as hereinaftermore fully d escribed.

' A in the drawing represents the frame, in which the shaft B of thegrinding-stone C is hung. This grinding stone is of suitable kind,material, and size. In the frame is formed a transverse socket, a, toreceive the transverse lower arm, b, of the main holder D 0f the guide.A screw, o, clamps the arm bin the socket a. The upper end of the holderD carries another longitudinal socket, d, for receiving the longitudinalarm o of the main guide E, a screw, f, serving to clamp the arm o in d.

The main holder is a horizontal bar projecting at an angle of aboutthirty degrees backward from the face-plane of the grindstone.

A lip, g, projects from the guide E parallel with the edge of the stone.

The adjustment of the arm b in the socket a serves to fit the lip g atthe requisite distance from the edge of any grinder of suitablediameter.

The drill to be ground is held against an arm, h," that projectsdownwardfrom the guide,

and against an adjustable curved bar, i, which is fitted upon the guideE, so as to slide on the same, a screw, j, serving to lock it in everydesired position.

The arms h and t' serve to hold the drill always in the same obliqueplane in which the guide projects from the stone. The drill is placedagainst the guide, as aforesaid, and with the end against the stone insuch manner that the cutting-edge is horizontal. It is then graduallyrocked, so as to raise the cuttingedge oft' the stone and grind the endfor forming the requisite inclined face on the same.

The lip gis rounded, as shown, to allow the convenient rocking of thedrill.

The adjustment of the arm e in el allows the guide to be set in or out,in accordance with the wear on the edge of the stone.

Having thus described my invention, I claim as new and desire to secureby Letters .Pat-

STEPHEN A. MORSE.

NVitnesses WM. BRADsHAw, C. l. SEABURY.

